Radicals are important intermediates in direct coal liquefaction.Certain radicals can cause the cleavage of chemical bonds.At high temperatures,radical fragments can be produced by the splitting of large organic molec...Radicals are important intermediates in direct coal liquefaction.Certain radicals can cause the cleavage of chemical bonds.At high temperatures,radical fragments can be produced by the splitting of large organic molecules,which can break strong chemical bonds through the induction pyrolysis of radicals.The reaction between the formation and annihilation of coal radical fragments and the effect of hydrogen-donor solvents on the radical fragments are discussed in lignite hydrogenolysis.Using the hydroxyl and ether bonds as indicators,the effects of different radicals on the cleavage of chemical bond were investigated employing density functional theory calculations and lignite hydrogenolysis experiments.Results showed that the adjustment of the coal radical fragments could be made by the addition of hydrogendonor solvents.Results showed that the transition from coal radical fragment to H radical leads to the variation of product distribution.The synergistic mechanism of hydrogen supply and hydrogenolysis of hydrogen-donor solvent was proposed.展开更多
Oil-coal slurry prepared in coal direct liquefaction is a dispersed solid-liquid suspension system. In this paper, some factors such as solvent properties, solid concentrations and temperatures, which affect viscosity...Oil-coal slurry prepared in coal direct liquefaction is a dispersed solid-liquid suspension system. In this paper, some factors such as solvent properties, solid concentrations and temperatures, which affect viscosity change of oil-coal slurry, were studied. The viscosity of coal slurry was measured using rotary viscometer, and the rheological properties have been investigated. The viscosity and rheological curves were plotted and regressed, respectively. The results show that the coal slurry behaves a pseudoplastic and thixotropic property. The rheological type of coal slurry was ascertained and its rheological equations were educed. The oil-coal slurry changes to non-Newtonian fluid from Newtonian fluid with the increasing of solid concentration.展开更多
基金The authors are grateful to the National Natural Science Foundation of China(Grant No.22038008)the 2030 Major Project Pilot Project from CHN Energy,China(Grant No.GJNY2030XDXM-19-13,2)for the financial suppor。
文摘Radicals are important intermediates in direct coal liquefaction.Certain radicals can cause the cleavage of chemical bonds.At high temperatures,radical fragments can be produced by the splitting of large organic molecules,which can break strong chemical bonds through the induction pyrolysis of radicals.The reaction between the formation and annihilation of coal radical fragments and the effect of hydrogen-donor solvents on the radical fragments are discussed in lignite hydrogenolysis.Using the hydroxyl and ether bonds as indicators,the effects of different radicals on the cleavage of chemical bond were investigated employing density functional theory calculations and lignite hydrogenolysis experiments.Results showed that the adjustment of the coal radical fragments could be made by the addition of hydrogendonor solvents.Results showed that the transition from coal radical fragment to H radical leads to the variation of product distribution.The synergistic mechanism of hydrogen supply and hydrogenolysis of hydrogen-donor solvent was proposed.
基金Project 2004CB217601 supported by the National Key Basic Research Development Plan (973) of China
文摘Oil-coal slurry prepared in coal direct liquefaction is a dispersed solid-liquid suspension system. In this paper, some factors such as solvent properties, solid concentrations and temperatures, which affect viscosity change of oil-coal slurry, were studied. The viscosity of coal slurry was measured using rotary viscometer, and the rheological properties have been investigated. The viscosity and rheological curves were plotted and regressed, respectively. The results show that the coal slurry behaves a pseudoplastic and thixotropic property. The rheological type of coal slurry was ascertained and its rheological equations were educed. The oil-coal slurry changes to non-Newtonian fluid from Newtonian fluid with the increasing of solid concentration.
